The present invention relates to a coupling which can form part of the structure of an ostomy appliance, and also to an ostomy appliance comprising such a coupling.
A great many appliances have already been proposed for the collection of bodily matter (faeces, urine, etc.) in persons who have undergone surgery of the gastrointestinal tract, of the ileostomy or colostomy type, or surgery of the urinary tract, of the urostomy type, or surgery necessitating the drainage of wounds or of intra-abdominal cavities, of the peritoneal or sub-peritoneal drainage type. Among these appliances, a basic distinction is made between:
appliances referred to as xe2x80x9cone-piecexe2x80x9d appliances because they consist of a collecting bag which comprises a skin protector provided with a pressure-sensitive adhesive and which is intended to be fixed on the user""s skin by way of this skin protector alone, and
appliances referred to as xe2x80x9ctwo-piecexe2x80x9d appliances which comprise a frontal sheet or xe2x80x9cbag holderxe2x80x9d intended to be fixed on the user""s skin and provided, for this purpose, with an adhesive pad, and a collecting bag which can be removably attached to this frontal sheet by means of a joining piece with which it is provided.
The ostomy appliances of the xe2x80x9ctwo-piecexe2x80x9d type have to satisfy certain conditions, some of which are inherently contradictory. Thus, although it is essential that the fixing of the collecting bag on the bag holder is secure in such a way as to prevent any inadvertent separation of this bag, particularly under the effect of the stresses exerted by the weight of the bodily matter with which it fills, and moreover that it guarantees perfect leaktightness of the appliance in relation to this matter, it is also desirable that the ostomy patients xe2x80x94who are often elderly subjects can, after a period of training by nursing staff, put the bag holder in place themselves, on the one hand, and, on the other hand, place the collecting bags on the bag holder, and this means that the manoeuvres for joining and disconnecting the bag and bag holder must be as simple and straightforward as possible.
To this end, two-piece appliances have been proposed, in a great many embodiments, in which the collecting bag and the bag holder are joined together by force-fitting, under the effect of a pressure applied by the patient, a joining piece, which is equipped with an annular sealing lip and is situated preferably on the bag, into a channel which has a shape and dimensions matching those of the said joining piece and which is formed by two other joining pieces situated preferably on the bag holder. These appliances, described in GB-A-1 571 657 and EP-A-0 171 255, for example, have the advantage that a single engagement operation ensures, on the one hand, the attachment of the bag and the bag holder and, on the other hand, the leaktightness of the appliance. However, in practice, to obtain satisfactory results, these appliances demand that the patient exert a considerable pressure on the bag, when placing it on the bag holder, and, consequently, on the area surrounding the stoma, which is generally very sensitive, sometimes very painful, so that the use of these appliances is not really satisfactory.
In an attempt to solve this problem, it has been proposed in GB-A-2 237 993 and GB-A-2 237 995 to improve this type of appliance by configuring the joining pieces of the collecting bag and of the bag holder in such a way that they are joined together, no longer by force-fitting, but by the joining piece of the bag snapping between the two joining pieces of the bag holder, and in such a way that their attachment is ensured by means of the end of the annular sealing lip of the joining piece of the bag pressing against a rib, likewise annular, situated on one of the joining pieces of the bag holder. Although these appliances do indeed allow the bag and the bag holder to be joined together without exerting pressure on the area surrounding the stoma, they nevertheless pose another problem, namely that in order to disconnect them, they require that a considerable pulling force be applied on the said bag, which, once again, can cause pain on account of the sensitivity of the area surrounding the stoma, and which can also cause partial or total tearing of the bag holder from the patient""s skin, rendering it unsuitable for further use.
Two-piece appliances have also been proposed in which the device for joining the collecting bag and the bag holder together comprises, on the one hand, two joining pieces, one of which is situated on the bag while the other is fixed on the bag holder and which, when they are brought into contact with one another, are intended to ensure the leaktightness of the appliance by virtue of the presence of a sealing lip or sealing joint or by virtue of the matching nature of their shapes and/or their dimensions, and, on the other hand, a member of the circular ring type which is generally connected to one of these two joining pieces and which, by different mechanisms (cam effect, clamping effect, etc.), ensures the attachment of the bag on the bag holder in such a way that these can be joined together and disconnected by means of applying moderate, if any, forces of pressure in one case and of traction in the other, on the bag. Such appliances are described in EP-A-0 255 310 and in WO-A-91/01118, for example.
The appliances of this latter type are not totally satisfactory either to the extent that, although belonging to the two-piece appliance type, they in fact comprise at least three elements for joining the collecting bag to the bag holder, a fact which significantly complicates their realization, both in terms of the manufacture of the various components from which they are made up and the assembly of these components, and substantially increases their production cost, whereas the long-term use of appliances by ostomy patients dictates that these appliances be relatively inexpensive.
Consequently, a general object of the invention is to make available an ostomy appliance in which the device for joining together and disconnecting the collecting bag and the bag holder is made up of only two elements, in such a way as to have a relatively low production cost, while at the same time satisfying all the conditions demanded of such an appliance, and, especially, ease of use, ease of handling, security of the attachment of the bag on the bag holder and leaktightness in relation to the bodily matter, and which not only permits positioning of the bag on the bag holder without applying pressure in the area surrounding the stoma, but also permits removal of this bag without the need to exert considerable pulling force.
It is also an object of the invention to make available such an appliance which, once the collecting bag and the bag holder have been joined together, allows the patient to modify the position of the bag in relation to the bag holder in a simple way and without risk, for example in order to adapt the orientation of the bag as a function of his/her activities or to make it easier to empty.
According to the invention, these objects are achieved by a coupling which can form part of the structure of an ostomy appliance and which comprises two elements which can be joined together removably, each including a base, equipped with a central opening, and a tubular joining piece surrounding the said opening, in which the joining piece of the first element comprises, on its internal face, an elastically deformable annular lip whose free end is directed towards the plane of the base of the said element, while the joining piece of the second element includes, on its external face, means for axial retention of the free end of this lip, which coupling is characterized in that it includes a locking member, and in that the means for axial retention of the free end of the annular lip occupy a sector of the circumference of the joining piece of the second element, of which the midpoint is situated diametrically opposite the said locking member under conditions of assembly and disassembly of the two elements of this coupling.
Thus, to join the two elements of the coupling together, the user, after ensuring that the locking member is in the unlocked position, begins by positioning the annular lip of the first element so that it bears on the means for axial retention of the second element in the zone diametrically opposite the locking member. He then pivots one element relative to the other until the joining pieces of the two elements are fully engaged with one another. It then suffices for him to lock the locking member so as to secure the two elements of the coupling. This joining together does not therefore require the application of any pressure.
To disconnect the two elements of the coupling, it suffices to perform the opposite procedure: to unlock the locking member, move the two elements of the coupling away from each other at right angles to the locking member in such a way as to pivot one of the elements of the coupling in relation to the other one, with the annular lip remaining bearing on the means for retention in the zone diametrically opposite the locking member; thus, with the pivoting, the lip can finally be disengaged completely by the simple effect of geometry and, consequently, without the need to exert any pulling forces.
According to an advantageous arrangement of the coupling according to the invention, the means for axial retention of the free end of the annular lip occupy a sector of the circumference of the joining piece of the second element corresponding to an angle of between about 180 and 320xc2x0 depending on the diameter of this joining piece, which is itself advantageously between about 25 and 100 mm. Thus, in the case of a joining piece having a diameter less than or substantially equal to 50 mm, the means for axial retention of the end of the annular lip will preferably occupy an angular sector of between 180 and 275xc2x0, whereas in the case of a joining piece of greater diameter, they will preferably extend over an angular sector of between 240 and 320xc2x0.
According to a preferred arrangement of the coupling according to the invention, the means for axial retention of the free end of the annular lip consist of a flange which extends radially, from the external face of the joining piece of the second element, outwards from this joining piece.
In a particularly preferred manner, this flange is a diminishing flange whose width is at its maximum at the midpoint of the sector which it occupies and decreases progressively in the direction of the ends of this sector.
To guarantee the locking of the two elements of the coupling, the latter advantageously comprises means for immobilizing the locking member in the locked condition.
According to another preferred arrangement of the coupling according to the invention, with the locking member being joined to one of the two elements, it is intended to cooperate, in response to the activation of a control mechanism joined to the same element as itself, with a bearing surface which is formed on the joining piece of the other of the two elements of this coupling.
According to a first preferred embodiment of the coupling according to the invention, the locking member and the control mechanism are joined to the second element of this coupling, and the locking member is intended to cooperate with a bearing surface which extends radially, from the external face of the joining piece of the first element, outwards from this joining piece.
According to an advantageous feature of this first preferred embodiment, the bearing surface intended to cooperate with the locking member is formed by the face, situated opposite the base of the first element, of a rib with bevelled faces projecting from the external face of the joining piece of this first element.
In a preferred manner, the rib with bevelled faces projecting from the external face of the joining piece of the first element extends over the entire circumference of this joining piece. Thus, when the ostomy appliance is in the condition of use, the locking of the two elements of the coupling is ensured irrespective of the position of the collecting bag in relation to the bag holder, so that the patient can modify this position, as he/she wishes, by rotating the said bag on the bag holder, without any risk of causing the said elements to unlock.
According to another advantageous feature of this first preferred embodiment, the locking member is in one piece with the control mechanism and consists of at least one rib with bevelled faces, of which one of the faces matches the face of the rib of the joining piece of the first element intended to serve as a bearing surface, and which projects from the face of the said control mechanism situated opposite the joining piece of the second element.
In a preferred manner, the control mechanism comprises an arm which is mounted so as to pivot about an axis formed by a pin with which it is provided, and which is engaged in an orifice formed in the base of the second element.
In this case, the second element advantageously comprises means for maintaining and guiding this arm in a plane parallel to that of its base.
These means for maintaining and guiding the arm advantageously comprise at least one stud projecting from that face of this arm situated opposite the base of the second element, having a free return end which determines a bearing face and which is adapted to pass through an oblong slot formed in the base of the second element, so that the said bearing face slides on a face of the said base situated on the side opposite the said arm.
In this case too, the arm advantageously includes, on its face situated opposite the base of the second element, at least one projecting piece adapted to cooperate with a nose formed on the external edge of this same base in order to ensure immobilization of the locking member in the locked condition.
According to yet another advantageous feature of this first preferred embodiment, the second element of the coupling moreover includes means which are able to limit the radial displacement of the bottom of the annular lip in the direction of the joining piece of the first element when the two elements of this coupling are joined together.
According to another preferred embodiment of the coupling according to the invention, the locking member is joined to the first element of this coupling and is intended to cooperate, in response to the activation of a control mechanism also joined to the said first element, with a bearing surface which extends radially, from the external face of the joining piece of the second element, inwards from this joining piece.
According to an advantageous feature of this preferred embodiment, the bearing surface intended to cooperate with the locking member is formed by the wall, situated opposite the base of the second element, of a recess formed in the thickness of the joining piece of this second element.
In a preferred manner, the recess formed in the thickness of the joining piece of the second element extends over the entire circumference of this joining piece. However, given that, in this embodiment, the locking member is joined to the first element of the coupling while the means for axial retention of the end of the annular lip of this first element are situated on the second element of this coupling, it is advantageous to provide for the presence, on the base of the second element, of two stops which are able to limit the rotation of one element relative to the other when these elements are joined together, in such a way as to prevent the locking member from being brought into cooperation with a portion of this recess which would be situated in the angular sector occupied by the said means for axial retention, thereby creating an area in which the joining pieces of the two elements of the coupling would at one and the same time be without means able to ensure their locking and without means able to axially retain the free end of the annular lip, and presenting an angular extension sufficient to cause inadvertent disconnection of these two elements.
According to another advantageous feature of this preferred embodiment, the locking member is in one piece with the activating mechanism and consists of a rod which is placed in a cylindrical opening passing through the joining piece of the first element, one end of which can be lodged in the recess formed in the thickness of the joining piece of the second element while its other end is integral with the activating mechanism.
In a preferred manner, this rod is threaded over all or part of its length and the activating mechanism is formed by a knurled wheel or the like which is able to permit its displacement by rotation in the cylindrical opening in which it is placed.
The invention also relates to an ostomy appliance, such as an appliance for ileostomy, colostomy or urostomy, or for post-surgical drainage of intra-abdominal spaces, of the peritoneal or sub-peritoneal drainage type, which appliance comprises a bag holder intended to be fixed around an artificial opening in the body of a user, and a bag which collects the bodily matter and which can be joined in a removable manner to the said bag holder, characterized in that it comprises a coupling as defined hereinabove.